Re: Re: Caller's Variables

That is, lexical variables that don't share a scope are unreachable.

Not strictly true since you can modify lexical variables with the help of PadWalker. Here's some code from the docs

sub increment_my_x {
    my $h = peek_my (1);
    ${$h->{'$x'}}++;
}

my $x=5;
increment_my_x;
print $x;  # prints 6
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Although you'd have to be quite a disturbed individual to use this sort of thing in ~~production~~ any code ;-)
HTH

_________ broquaint

Comment on Re: Re: Caller's Variables Download Code

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Re: Re: Re: Caller's Variables by shotgunefx (Parson) on Jul 08, 2002 at 20:21 UTC
I could see one or two valid uses. The one place I've used it for production was a tied hash package. We wanted to be able to alias package vars in the hash values with vars from the caller. Retrofitting this to older code was a pain as they HAD to be package variables so we changed the alias sub to look at caller's lexicals and then the package vars. -Lee "To be civilized is to deny one's nature." Update While on the subject, I should mention a bug/feature of PadWalker. It will NOT see all lexicals visable where the subroutine is called if you have a bare block `#!/usr/bin/perl -w use strict; use PadWalker qw(peek_my); my ($oa,$ob) = ("Outer One", "Outer Two"); { my $inb = "Bare Block"; # Will not be seen by peek_my peeper(); } sub peeper { my $c = peek_my(1); print "Lexicals:\n", (map { "Found $_ with value $c->{$_}\n" } sor +t keys %$c ),"\n"; }` [download]	[reply] [d/l]

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Re: Re: Re: Caller's Variables
by shotgunefx (Parson) on Jul 08, 2002 at 20:21 UTC

Update

#!/usr/bin/perl -w
use strict;

use PadWalker qw(peek_my);


my ($oa,$ob) = ("Outer One", "Outer Two");

{
    my $inb = "Bare Block"; # Will not be seen by peek_my
    peeper();

}

sub peeper {
   my $c = peek_my(1);
   print  "Lexicals:\n", (map { "Found $_ with value $c->{$_}\n" } sor
+t keys %$c ),"\n";

}
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